Discussion Forum

Hello,

I'm right now working on a project, where I had to 3D-Scan a throax model and use it for simulation of the heart dipol. The model is basically a real body sized container filled with a NaCl - solution. For simulating the heart dipol 3 electrode pairs are placed in the solution. A signal will be applied to the electrodes to create the heart dipol, but for the beginning I just wanted to apply a pulse for one electrode pair. To have a realistic electrode-electrolyte boundary a contact impedance was applied. The parameters were determined by a EIS(Electro impedance spectroscopy) measurement.

So now to my question. If the pulse is applied (in a time dependent study) as a potential the System runs perfectly, but if the pulse is defined as a current source the system seems to be numerical unstable. What are possible reasons for that? Further information/Question: * I have huge differences in conductivity values. For the source electrodes I have defined a boundary by the contact impedance, but I also use measurement electrodes at the body surface. For those measurement electrodes I haven't applied any contact impedance, because the current at this region should be small, it should be possible to neglect that. Or could this be a problem? * What is the huge difference for the simulation itself for calculation with a current source compared to a voltage source? * I'm using terminals to define the sources and sinks. For the current source I'm using a current terminal (defines the source) and a potential terminal defining the sink (0 V = ground)

I have attached the model as packed *.zip-file, because the model was to big. You need all three parts for unziping.

Thank you for any help!

Kindly Regards,

Lukas